What is the definition for variation?

Answer 1

Any difference between two indivisuals of the same species

For example:

Eye colour, Hair colour etc

is called Variation

Answer 2

Variation refers to the degree of difference or diversity among individuals within a population or species. It can involve differences in traits, characteristics, or behaviors, which can be shaped by genetic, environmental, and other factors. Studying variation is important in understanding evolution, adaptation, and biodiversity.